Uplink channel design with coverage enhancements

Abstract

Aspects of the present disclosure provide techniques for providing uplink channel coverage enhancements for wireless devices. An example method generally includes determining a power difference value based on a target preamble received power level and a maximum preamble transmit power level, selecting a bundling size for uplink transmissions based on the determined difference, and sending the uplink transmissions, in accordance with the selected bundling size.

What is claimed is: 
     
         1 . A method for wireless communications by a user equipment (UE), comprising:
 determining a power difference value based on a target preamble received power level and a maximum preamble transmit power level;   selecting a bundling size for uplink transmissions based on the determined power difference value; and   sending the uplink transmissions, in accordance with the selected bundling size.   
     
     
         2 . The method of  claim 1 , wherein the power difference value is also based on a downlink path loss estimate. 
     
     
         3 . The method of  claim 1 , wherein the uplink transmission comprises RACH preamble transmission. 
     
     
         4 . The method of  claim 3 , wherein the RACH preamble transmission comprises a RACH repetition sequence. 
     
     
         5 . The method of  claim 3 , wherein a bundling size for uplink transmission is selected based on the determined power difference value only if the power difference value is greater than zero. 
     
     
         6 . A method for wireless communications by a user equipment (UE), comprising:
 sending a first uplink transmission at a power level and a bundling size; and   adjusting the bundling size for one or more subsequent uplink transmissions, if the first uplink transmission fails.   
     
     
         7 . The method of  claim 6 , wherein the first uplink transmission comprises a RACH preamble transmission. 
     
     
         8 . The method of  claim 7 , wherein the RACH preamble transmission comprises a RACH repetition sequence. 
     
     
         9 . The method of  claim 6 , wherein adjusting the bundling size for one or more subsequent uplink transmissions comprises:
 determining a power difference value based on a target preamble received power level and a maximum preamble transmit power level; and   selecting a bundling size for uplink transmissions based on the determined power difference value.   
     
     
         10 . The method of  claim 6 , wherein adjusting the bundling size for one or more subsequent uplink transmissions comprises:
 adjusting the bundling size for one or more subsequent uplink transmissions after transmission power for a previous uplink transmission has reached a predetermined level.   
     
     
         11 . The method of  claim 10 , wherein the predetermined level corresponds to a maximum uplink transmission power level. 
     
     
         12 . The method of  claim 10 , further comprising:
 reducing transmission power for subsequent uplink transmissions after increasing the bundling size.   
     
     
         13 . A method for wireless communications by a user equipment (UE), comprising:
 determining a transmission power level for an uplink transmission based, at least in part, on a transmission power level parameter that has a first value for uplink transmissions without bundling and a second value for uplink transmissions with bundling; and   sending the uplink transmission, in accordance with the determined transmission power level.   
     
     
         14 . The method of  claim 13 , wherein the uplink transmission comprises a RACH preamble transmission. 
     
     
         15 . The method of  claim 14 , wherein the RACH preamble transmission comprises a RACH repetition sequence. 
     
     
         16 . The method of  claim 13 , wherein the uplink transmission comprises a physical uplink shared channel (PUSCH) transmission. 
     
     
         17 . The method of  claim 13 , further comprising receiving at least one of the first and second values in a broadcast system information block (SIB). 
     
     
         18 . A method for wireless communications by a user equipment (UE), comprising:
 determining a bundling size to use for a random access channel (RACH) procedure, wherein different bundling sizes are used for contention-based and non contention-based RACH procedures; and   performing the RACH procedure, in accordance with the determined bundling size.   
     
     
         19 . The method of  claim 18 , wherein a bundling size for a contention based RACH procedure is determined based, at least in part, on downlink path loss estimations. 
     
     
         20 . The method of  claim 18 , wherein a bundling size for a non-contention based RACH procedure is indicated by base station. 
     
     
         21 . The method of  claim 18 , wherein:
 the RACH procedure is ordered by a base station; and   the base station indicates a bundling size to use for the RACH procedure in a physical downlink control channel (PDCCH).